1. Field of the Invention
The present invention relates to a communication terminal device and a computer device and specifically, relates to a portable communication terminal device which has a function equivalent to a mouse used as a pointing device of the computer device and can verify the reliability of the computer device.
2. Description of the Related Art
When a user uses a computer which is not the user's own at a place where the user goes or the like, if whether the computer is reliable can be verified, the user can use the computer for purposes critical in security such as electronic commerce and access to a company's private network, thus improving the convenience of the user.
Specifications to prove a computer to be reliable have been proposed by TCPA (TCG) (for example, see Compaq Computer Corporation, Hewlett-Packard Company, IBM Corporation, Intel Corporation, Microsoft Corporation, “Trusted Computing Platform Alliance (TCPA) Main Specification Version 1.1b”, 22 Feb. 2002, http://www.trustedcomputing.org/docs/main %20v11b.pdf). However, these specifications are based on cryptographic processing, and an entity challenging the reliability of the computer also must have a cryptographic capability. Specifically, to verify the reliability of the computer at the place where the user goes, the user has to bring any equipment including the cryptographic capability. Herein, the equipment needs to provide excellent portability and reliability for the user.
A method in which a user verifies the reliability of the computer using a smart card has been therefore disclosed (for example, see “Trusted Computing Platforms: TCPA technology in context”, Siani Pearson, et al, Published July, 2002 by Prentice Hall PTR, ISBN 0-13-009220-7”. The smart card provides excellent portability and tamper resistance, which is reliable equipment for the user. However, the smart card does not include an I/O function and needs a device to transmit results of reliability verification of the computer to the user. In “Trusted Computing Platforms: TCPA Technology in context”, a user previously stores in the smart card secret information (a particular image or word) that only the user can know, and the smart card challenges the computer. Only when obtaining the result that the computer is reliable, the smart card transmits the secret information to the computer. The secret information is displayed on a display of the computer, so that the user can verify the reliability of the computer.
This method allows the user to verify the reliability of the computer before the computer is brought into use but does not provide a mechanism allowing the user to easily know that the reliability of the computer continues while the computer is in use. Accordingly, for example, it is highly possible that the user does not know if the computer is invaded by a virus during use and carries out an operation dangerous to the security. Moreover, when the secret information that only the user can know is repeatedly used, the secret information used in the past remains in the computer, and a malicious person can use the secret information to cause a unreliable computer to display the same and mislead the user.
In the light of the aforementioned problem, an object of the present invention is to provide a communication terminal device and a computer device which can perform easy, continuous, and sure verification whether a computer is reliable when the computer is used.